It now creates own internal WebGLRenderer and manages render targets scaling internally.

More garbage collection friendly Box2.distanceToPoint(), Box3.distanceToPoint() and Vector3.distanceToSquared()

Conflicts:
	src/core/Box3.js

add equals, clone to Box2, Box3, Plane and Sphere. Adopt +Inf/-Inf in Box2 and Box3 per @mrdoob'd recommendation.  Begin Box3 unit test.

Vector2: setX, setY, Vector4: setX, setY, setZ, equals.  Unit tests for Vector2, Vector3 and Vector4.

Surprisingly the effect on performance is minimal, despite doing quite much less operations. Yet again raw math performance doesn't seem to matter.